2004 Merc 125 w/no high speed

[robinr011]

Hello I have a 2004 Merc 125 SN-OT645864 that I am having some difficulties getting to run correctly. Got it back from winter storage and took it out and found that the motor will not go over 1500 rpm WOT. It is quite weird as the eng doesn't seem to surge it is just a very steady 1500 rpm. I have confirmed spark of all 4 cyl, (changed out the trigger), compression is 120 psi in all cylinders, and confirmed gas is water free. It does not seem to want to idle and will stall but will continue to run if throttle is advanced. Any thoughts / suggestions would be great before I start taring down the carbs.

Thanks
Robert

[JOE54]

sounds like fuel system problem

[robinr011]

Yeah that was the next thing Joe... It is interesting because I would think that the eng would surge more with a fuel related problem. Do you know what the torque spec is for the carb to intake manifold is? The manual states 40Ftp but I know that cannot be right.

Thanks for the help.
Robinr011

[robinr011]

Just a quick update to close this issue.. After checking both electrical and fuel systems, the problem turned out to be the link lever between the throttle lever and the throttle cam asm. The two clips that keep the lever in place were broken, (age I guess), and every time I would attempt to throttle-up the link would pull out of one side or the other. it was difficult to spot because the link would remain in a horizontal position even when detached not drawing your attention unless you really looked at it.

I personally was convinced it had something to do with the rev limiter.

Robinr011